Although supernova 1987A was first spotted two decades ago, Hubble is the only existing observatory that can make out each "bead" in the dead star's unusual "necklace," as seen in this December 2006 picture.

Pink material in the middle of the ring is debris left behind when the massive star exploded. Astronomers think the ring is an outer layer of matter that the star had shed 20,000 years before it died. The shock wave from the blast is now heating up regions of that ring, creating the glowing "pearls."